The first targeted therapy developed for any type of cancer, radioactive iodine (RAI) treatment for papillary thyroid cancer is a form of internal radiation therapy that capitalizes on a unique characteristic of thyroid cells.
Almost all papillary thyroid cancers are primarily treated with the removal of either the entire thyroid gland (total thyroidectomy) or half of the thyroid gland (thyroid lobectomy). Patients who had total thyroidectomy can be treated with RAI. RAI treatment may be administered weeks, months or years after surgery to help prevent a cancer recurrence. Some patients require more than one RAI treatment.
How does RAI treatment work?
The function of the thyroid gland is to absorb iodine and convert it into two hormones, thyroxine (T4) and triiodothyronine (T3), which are utilized by the body to control growth, repair cellular damage and support metabolism. Unlike healthy thyroid cells, papillary thyroid cancer cells do not produce thyroid hormones, but they may still have the surface “keyhole” (symporter) that allows iodine to pass into the cell.
RAI treatment involves having a patient swallow a capsule with radioactively charged iodine. After the RAI is digested, it enters the bloodstream and circulates throughout the body to reach widespread cancer cells. Papillary thyroid cancer cells that have the iodine symporter may take in the radioactive iodine, which delivers a local radiation treatment.
When is RAI considered for treating papillary thyroid cancer?
While RAI treatment can be effective for preventing the recurrence of papillary thyroid cancer, it is not appropriate for every patient. RAI may be considered if:
- Papillary thyroid cancer has spread beyond the thyroid gland capsule and invaded nearby soft tissues
- Papillary thyroid cancer has spread to lymph nodes in the neck
- It is necessary to destroy additional thyroid tissue that is producing thyroglobulin
- Papillary thyroid cancer has spread to a distant site, such as the lungs, liver or bones
To prepare for RAI treatment, a papillary thyroid cancer patient will need to take shots of a man-made thyroid-stimulating hormone (Thyrogen) or temporarily discontinue thyroid hormone replacement therapy. Additionally, the patient will be instructed to consume a low-iodine diet. If the body is starved of iodine beforehand, the treatment is more effective.
If you would like to explore your treatment options for papillary thyroid cancer, which may include radioactive iodine treatment, you can meet with a specialist in the thyroid clinic at Moffitt Cancer Center with or without a referral. To request an appointment, call 1-888-663-3488 or submit a new patient registration form online.